lib/Catalyst/Model/DBIC/Schema/Trait/Replicated.pm

   1 package Catalyst::Model::DBIC::Schema::Trait::Replicated;
   2
   3 use namespace::autoclean;
   4 use Moose::Role;
   5 use Moose::Autobox;
   6 use Carp::Clan '^Catalyst::Model::DBIC::Schema';
   7
   8 use Catalyst::Model::DBIC::Schema::Types 'ConnectInfos';
   9
  10 =head1 NAME
  11
  12 Catalyst::Model::DBIC::Schema::Trait::Replicated - Replicated storage support for
  13 L<Catalyst::Model::DBIC::Schema>
  14
  15 =head1 SYNOPSiS
  16
  17     __PACKAGE__->config({
  18         traits => ['Replicated']
  19         connect_info =>
  20             ['dbi:mysql:master', 'user', 'pass'],
  21         replicants => [
  22             ['dbi:mysql:slave1', 'user', 'pass'],
  23             ['dbi:mysql:slave2', 'user', 'pass'],
  24             ['dbi:mysql:slave3', 'user', 'pass'],
  25         ],
  26         balancer_args => {
  27           master_read_weight => 0.3
  28         }
  29     });
  30
  31 =head1 DESCRIPTION
  32
  33 Sets your storage_type to L<DBIx::Class::Storage::DBI::Replicated> and connects
  34 replicants provided in config. See that module for supported resultset
  35 attributes.
  36
  37 The default L<DBIx::Class::Storage::DBI::Replicated/balancer_type> is
  38 C<::Random>.
  39
  40 Sets the
  41 L<DBIx::Class::Storage::DBI::Replicated::Balancer::Random/master_read_weight> to
  42 C<1> by default, meaning that you have the same chance of reading from master as
  43 you do from replicants. Set to C<0> to turn off reads from master.
  44
  45 =head1 CONFIG PARAMETERS
  46
  47 =head2 replicants
  48
  49 Array of connect_info settings for every replicant.
  50
  51 =cut
  52
  53 has replicants => (
  54     is => 'ro', isa => ConnectInfos, coerce => 1, required => 1
  55 );
  56
  57 after setup => sub {
  58     my $self = shift;
  59
  60 # check storage_type compatibility (if configured)
  61     if (my $storage_type = $self->storage_type) {
  62         my $class = $storage_type =~ /^::/ ?
  63             "DBIx::Class::Storage$storage_type"
  64             : $storage_type;
  65
  66         croak "This storage_type cannot be used with replication"
  67             unless $class->isa('DBIx::Class::Storage::DBI::Replicated');
  68     } else {
  69         $self->storage_type('::DBI::Replicated');
  70     }
  71
  72     $self->connect_info->{balancer_type} ||= '::Random'
  73         unless $self->connect_info->{balancer_type};
  74
  75     unless ($self->connect_info->{balancer_args} &&
  76             exists $self->connect_info->{balancer_args}{master_read_weight}) {
  77         $self->connect_info->{balancer_args}{master_read_weight} = 1;
  78     }
  79 };
  80
  81 sub BUILD {}
  82 after BUILD => sub {
  83     my $self = shift;
  84
  85     $self->storage->connect_replicants(map [ $_ ], $self->replicants->flatten);
  86 };
  87
  88 =head1 SEE ALSO
  89
  90 L<Catalyst::Model::DBIC::Schema>, L<DBIx::Class>,
  91 L<DBIx::Class::Storage::DBI::Replicated>,
  92 L<Cache::FastMmap>, L<DBIx::Class::Cursor::Cached>
  93
  94 =head1 AUTHOR
  95
  96 Rafael Kitover, C<rkitover at cpan.org>
  97
  98 =head1 COPYRIGHT
  99
 100 This program is free software, you can redistribute it and/or modify it
 101 under the same terms as Perl itself.
 102
 103 =cut
 104
 105 1;